微波Ⅲ型爆发与日冕物质抛射的统计分析

Statistics and Analysis on the Relation Between Microwave Type Ⅲ Bursts and CME Events

对国家天文台2.6～3.8GHz频谱仪在第23太阳活动周上升段(1996～1998)记录到的Ⅲ型爆发,与日冕物质抛射(CME)作了统计分析。发现微波Ⅲ型爆发可能是CME的先兆现象,并讨论了它们的辐射机制。

The microwave type Ⅲ bursts and the CME are statistically analysed in the present article.The observational data were recorded with the 2.6-3.8GHz spectrograph at the National Observations during the ascending branch of the 23rd solar cycle.It is found that microwave type Ⅲ bursts may be indications of the ejection of coronal matter.The author holds that in the events where CME and type Ⅲ bursts coexist,those in which type Ⅲ bursts occur before CME may be caused by the production of high energy electrons before the CME shock waves and when the shock waves get to the open magnetic field lines,the (3R) radio bursts start.Type Ⅱ bursts are also produced by the accelerated electronic streams and both of type Ⅱ and Ⅲ bursts all have relation to high energy electrons.The electronic streams are accelerated in the shock front and then propagate in the upward and downward regions where they excite the Langmuir waves and then change into radio waves.In a word,the activities occured before the ejection may be incentive to CME while Hα flares may be caused by the magnetic field reconnection after the ejection.In addition,all the types,intensities and positions of the correlaed activities before and after the beginning of ejection will have a great change,showing that these activities occured in the different periods of the ejection may have different physical mechanisms.